protein graphics

What we need is a program that can plot and manipulate proteins
so helices becomes cylinders and strands becomes arrows which seem
to be standard. We have InsightII but it cannot do that.
Do anyone know of such a program possible in public domain???
a direct email will be nice.
many thanks
--
Jan Hansen
Center for Biological Sequence Analysis
Laboratory for Infectious Diseases
Department of Physical Chemistry
The Technical University of Denmark
Building 206
DK-2800 Lyngby
Denmark
Phone: +45 4593 1222 ext. 2485 (tone)
Fax: +45 4593 4808
E-mail: janhan at cbs.dtu.dk